He may cut a pensive figure, but don't be fooled - a dark and troubled soul Mr Aaron Tveit is not. "I don't walk around scowling at people," he laughs, defending the moody, monochrome results of last month's shoot with photographer Mr Billy Kidd. "I think I'm a nice guy!"

He's certainly had time to practise. The 29-year-old actor, who cut his teeth on Broadway before branching out into TV and film, has the "nice guy" thing down to a fine art. Clean-cut, athletic and immaculately coiffed, the born-and-bred New Yorker looks every bit the matinée idol and, as is clear within moments of meeting him, he's got the charm and easygoing personality to match. So what's with the frown?

"I had a great time on the shoot," Mr Tveit explains. "But he [Mr Kidd] told me early on that he was looking for something more brooding, more atmospheric. From my point of view, it was a lot of fun to go in that direction because it's definitely part of me, and something I don't get to do a lot." He has a point. The world of musical theatre isn't known for its serious dramatic roles, and his CV largely reflects that, with parts in Hairspray, Rent and Wicked and a lead in the big-budget Broadway production of Catch Me if You Can. All things considered - the nice-guy image, the all-singing, all-dancing background - Mr Tveit's next big gig, as a rookie undercover FBI agent in the upcoming USA Network series Graceland, will be a testament to his versatility as an actor.

I don't walk around scowling at people. I think I'm a nice guy!

Versatility was certainly an attribute that he was required to display throughout Graceland's filming process, coinciding as it did with his most high-profile role to date, in the 2012 screen adaptation of Les Misérables. "That year was... really interesting," he says of his time spent shuttling between drug busts in Miami and revolutions on the streets of Paris. "I ended up getting the roles in Graceland and Les Mis two days apart. I worked between the two - it was such a thrill to be constantly challenged."

Les Mis was, in many ways, the perfect vehicle for Mr Tveit to make the leap from stage to screen. He had done it before, most notably with a recurring role in Gossip Girl as politically ambitious (and delightfully named) Trip van der Bilt. But as doomed revolutionary leader Enjolras, he landed a part that not only placed him in one of the year's most talked-about movies, but also played to his vocal strengths. Much has been made of director Mr Tom Hooper's decision to record all singing parts during filming, an unconventional move that drew dynamic but occasionally unpolished performances from his cast. It's a point that Mr Tveit acknowledges. "Doing take after take is not really conducive to giving your best performance," he says. "But that's definitely something that Tom understood. He felt that the imperfections, at times, were actually where the emotion was going to come from." That's easy for him to say, of course. Mr Tveit has been training his voice since the age of 16, and it's hard to imagine that too much criticism was served in his direction.

the work

LES MISÉRABLES

Mr Tveit as Enjolras, the leader of Les Amis de l'ABC, in the 2012 musical drama

graceland

Mr Tveit as undercover FBI agent Mike Warren in this summer's television series

Gossip Girl

Mr Tveit as Trip van der Bilt with Ms Blake Lively as Serena van der Woodsen in the 2009 season

Howl

Mr Tveit as Beat poet Mr Peter Orlovsky with Mr James Franco as Mr Allen Ginsberg in the 2010 film

Despite his burgeoning screen career, it's on stage that Mr Tveit feels most at home - for now. It's also where he finds his most devoted fan base. His status as a hot commodity on Broadway was recently confirmed when a six-night cabaret run at 54 Below sold out in a matter of minutes. Two nights into the run when we speak, and preparing for the third, he's clearly in his element. "I'm telling my life story through songs that mean something to me," he explains. "I sing 'Something's Coming' from West Side Story, for example, which is a song I first performed at 16. Doing that show was the first time that I really thought, 'There might be something here. There might be a future.'" And what about that future? "I never set out to do anything but just be able to work and do something that I love." It sounds as if he's got plenty to smile about.